RSPA/OPS is issuing this advisory bulletin to owners and operators of gas and hazardous liquid pipeline systems on the potential for unauthorized excavations and the unauthorized installation of acoustic monitoring devices or other data acquisition devices on pipeline facilities. These devices are used by entities that hope to obtain market data on hazardous liquid and gas movement within the pipelines. Recent events have disclosed that devices were physically installed on pipelines without the owners permission. Operators must control construction on pipeline right-of-ways and ensure that they are carefully monitored to keep pipelines safe. This is in line with our efforts to prevent third-party damage as reflected by our support of the Common Ground Alliance, which is a nonprofit organization dedicated to shared responsibility in damage prevention and promotion of the damage prevention Best Practices. This advisory bulletin emphasizes the need to ensure that only authorized and supervised excavations are undertaken along the nation’s pipeline systems.